graph.swift

        // create graph
        var graph = CPTXYGraph(frame: CGRectZero)
        graph.title = "Hello Graph"
        graph.paddingLeft = 0
        graph.paddingTop = 0
        graph.paddingRight = 0
        graph.paddingBottom = 0
        // hide the axes
        var axes = graph.axisSet as CPTXYAxisSet
        var lineStyle = CPTMutableLineStyle()
        lineStyle.lineWidth = 0
        axes.xAxis.axisLineStyle = lineStyle
        axes.yAxis.axisLineStyle = lineStyle
        
        // add a pie plot
        var pie = CPTPieChart()
        pie.dataSource = self
        pie.pieRadius = (self.view.frame.size.width * 0.9)/2
        graph.addPlot(pie)
        
        self.graphView.hostedGraph = graph